1. Technical Field
An aspect of the present invention relates to an image processing device, a display system, an electronic apparatus, and an image processing method.
2. Related Art
Recently, LCD (Liquid Crystal Display) panels using liquid crystal elements as display elements or display panels (display devices) using organic light emitting diodes (hereinafter, abbreviated as “OLED”) (light-emitting elements in a broad sense) as display elements have been widely spread. The OLED has a higher response speed than that of the liquid crystal element and improves the contrast ratio. By using the display panel in which such OLEDs are arranged in a matrix shape, it is possible to display an image with a large viewing angle and high image quality.
However, when the time in which the same light-emitting element is lit with the same brightness lasts longer such as when a still image is displayed for a long time, a so-called burn-in phenomenon occurs even in the display panel using the OLED, thereby deteriorating the image quality. A technique of preventing the burn-in phenomenon in the display panel using the OLED is disclosed, for example, in JP-A-2007-304318 and JP-A-2008-197626.
JP-A-2007-304318 discloses an OLED display device in which a display position is shifted by a predetermined distance at a predetermined interval of time while controlling the gray scale of an image on the basis of a current value applied as an image signal or a length of time for applying a constant current. JP-A-2008-197626 discloses a technique of reducing a visual symptom for changing a refresh rate of a display.
On the other hand, the above-mentioned high-speed response characteristic of the OLED can enhance the usability of frame rate control on the OLED. For example, when the frame rate control is performed at the time of displaying an image on a display panel using the OLED, more gradation in gray scale can be expressed, thereby displaying an image with higher image quality, in comparison with the case where the frame rate control is performed at the time of displaying an image on an LCD panel. In this way, by performing the frame rate control, it is possible to prevent the burn-in phenomenon and to improve the image quality.
However, in the techniques disclosed in JP-A-2007-304318 and JP-A-2008-197626, the above-mentioned control is performed regardless of the type of an image input. Accordingly, the image quality may not be improved or the burn-in phenomenon may not be satisfactorily prevented, depending on the display panels or the display images.